Meta-analysisindependent cross-checkabstract checked★ key study I-SOD-103 in-depth review
Swapping sugary for diet drinks helped weight in trials
Association of Low- and No-Calorie Sweetened Beverages as a Replacement for Sugar-Sweetened Beverages With Body Weight and Cardiometabolic Risk: A Systematic Review and Meta-analysis.
Overview
McGlynn ND et al.. JAMA Netw Open 2022 · PMID 35285920 · DOI 10.1001/jamanetworkopen.2022.2092
In 17 randomised trials, replacing sugary drinks with low- or no-calorie drinks lowered weight by about 1 kg, similar in direction to water.
Does the study support the specific claim? No · Methodological quality: high
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Compare diet drinks, sugary drinks and water as substitutes.
- How was the study done?
Network meta-analysis of randomised trials.
- How many people, animals or samples were studied?
1733 adults with overweight or obesity.
- What was actually found?
Diet drinks instead of sugary drinks: about 1 kg less weight and less liver fat.
- How large was the observed effect?
-1.06 kg (-1.71 to -0.41).
- What do the results mean in everyday life?
For heavy soda drinkers, diet drinks can be a step down; water remains first choice.
- What are the study's limitations?
Short trials; several authors with industry links.
- What does it say about Elawady's specific claim?
Weakens the claim that diet soda is clearly harmful.
- Do the results apply to Germany and Europe?
Applicable.
- What can explicitly not be concluded from this study?
Cannot show long-term safety.
Scientific in-depth review
1. Full reference
- Authors
- McGlynn ND et al.
- Journal
- JAMA Netw Open
- Year
- 2022
- Identifier
- PMID 35285920 DOI 10.1001/jamanetworkopen.2022.2092
- Verification
- verified – PubMed efetch 2026-10-26 + Crossref 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
Commissioned by the Diabetes and Nutrition Study Group of the EASD and CIHR-funded; full-text disclosures list numerous food- and sweetener-industry links of senior authors (e.g. International Sweeteners Association, Calorie Control Council, Tate and Lyle fund).
2. Research question
Are LNCSBs as substitutes for SSBs associated with improved weight and cardiometabolic risk similar to water?
3. Study design and population
- Study design
- Meta-analysis – Systematic review and network meta-analysis of RCTs >=2 weeks (Medline, Embase, CENTRAL to 26 December 2021), GRADE
- Population
Adults with overweight or obesity at risk for or with diabetes
- Country
International
- Period
to 26 December 2021
- Sample size
17 RCTs, 24 comparisons, 1733 adults
- Inclusion and exclusion criteria
RCTs comparing LNCSB, SSB and/or water
4. Methods and endpoints
- Exposure / intervention
LNCSB replacing SSB
- Comparator
SSB; water
- Endpoints
Body weight; adiposity; glycaemia; lipids; blood pressure; NAFLD markers; uric acid
- Statistical methods
Frequentist random-effects network meta-analysis; GRADE
5. Actual results
- Results
LNCSB for SSB: body weight MD -1.06 kg (-1.71 to -0.41), BMI -0.32, body fat -0.60%, intrahepatocellular lipid SMD -0.42 (moderate certainty for weight). Water for SSB: no significant association. LNCSB for water: no association except HbA1c +0.21% (0.02-0.40) and systolic BP -2.63 mmHg.
- Absolute risks
not applicable
- Authors' conclusion
Using LNCSBs as an intended substitute for SSBs was associated with small improvements in body weight and cardiometabolic risk factors without evidence of harm.
6. Strengths
- RCTs only
- GRADE
- Network design compares water and LNCSB
7. Weaknesses
- Short to moderate duration
- Industry links of several authors
- Inconsistency in some comparisons (full-text limitations)
- No hard endpoints
8. Risk of bias
- Orienting tool
- AMSTAR 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Methodologically strong but conflicts of interest and short trials.
9. Assessment of the statistical interpretation
Weight difference CI symmetric (stats/C-SOD-10_mcglynn.py). Benefit reflects removal of sugar calories; says nothing about long-term mortality.
10. Relevance to the specific claim
Contradicts the harm side of C-SOD-10 for intermediate outcomes: replacing sugary soda with diet soda improved weight in RCTs; cited by ADA 2026 (ref. 181).
11. Independent contrary findings
Observational mortality associations (I-SOD-101, I-SOD-120, A-SOD-17) and WHO 2023 conditional recommendation against NSS for weight control.
12. Transferability to Germany and Europe
Commissioned for EASD guidelines; applicable.
13. Overall methodological judgement
Strongest randomised evidence on the question; supports short-to-moderate-term substitution, not long-term safety claims.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | some concerns |
| Precision of results | moderate |
| Directness | direct |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | mixed |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Long-term outcomes; effects in people without obesity.
15. Linked fact checks
- Diet soda is not a safe alternative to sugary soda: artificially sweetened drinks are linked to higher mortality, especially circulatory deaths. – Studies contradicting or limiting the claim